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Evaluate each function at the given value.

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Evaluate each function at the given value.

1) f (x) = −x^3 + 6x − 7 at x = 2
2) f (x) = x^3 + x^2 − 5x − 6 at x = 2
3) f (a) = a^3 + 3a^2 + 2a + 8 at a = −3
4) f (a) = a^3 + 5a^2 + 10a + 12 at a = −2
asked Oct 26, 2018 in ALGEBRA 2 by anonymous

1 Answer

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1) 
f (x)  =  − x^3 + 6x − 7
f (2)  =  − (2)^3 + 6(2) − 7
        =  − 8 + 12 − 7
        =  12 − 15
        =  - 3
2) 
f (x)  =  x^3 + x^2 − 5x − 6
f (2)  =  (2)^3 + (2)^2 − 5(2) − 6
        =  8 + 4 − 10 − 6
        =  12 − 16
        =  − 4
3) 
f (a)  =  a^3 + 3a^2 + 2a + 8
f (-3)  =  (-3)^3 + 3(-3)^2 + 2(-3) + 8
         =  - 27 + 3(9) - 6 + 8
         =  - 27 + 27 - 6 + 8
         =  2
4)
f (a)  =  a^3 + 5a^2 + 10a + 12
f (-2)  =  (-2)^3 + 5(-2)^2 + 10(-2) + 12
          =  - 8 + 5(4)  - 20 + 12 
          =  - 8 + 20  - 20 + 12 
          =  32 - 28
          =  4
Answer :
f (2)  = - 3
2)  f (2)  =  - 4
3)  f (-3)  =  2
4)  f (-2)  =  4
answered Oct 27, 2018 by homeworkhelp Mentor
edited Oct 27, 2018 by homeworkhelp

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